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<a name="1" href="#1">1</a>   <strong>package</strong> <a href="../../../../org/apache/torque/oid/package-summary.html">org.apache.torque.oid</a>;
<a name="2" href="#2">2</a>   
<a name="3" href="#3">3</a>   <em class="comment">/*</em>
<a name="4" href="#4">4</a>   <em class="comment"> * Licensed to the Apache Software Foundation (ASF) under one</em>
<a name="5" href="#5">5</a>   <em class="comment"> * or more contributor license agreements.  See the NOTICE file</em>
<a name="6" href="#6">6</a>   <em class="comment"> * distributed with this work for additional information</em>
<a name="7" href="#7">7</a>   <em class="comment"> * regarding copyright ownership.  The ASF licenses this file</em>
<a name="8" href="#8">8</a>   <em class="comment"> * to you under the Apache License, Version 2.0 (the</em>
<a name="9" href="#9">9</a>   <em class="comment"> * "License"); you may not use this file except in compliance</em>
<a name="10" href="#10">10</a>  <em class="comment"> * with the License.  You may obtain a copy of the License at</em>
<a name="11" href="#11">11</a>  <em class="comment"> *</em>
<a name="12" href="#12">12</a>  <em class="comment"> *   <a href="http://www.apache.org/licenses/LICENSE-2.0" target="alexandria_uri">http://www.apache.org/licenses/LICENSE-2.0</a></em>
<a name="13" href="#13">13</a>  <em class="comment"> *</em>
<a name="14" href="#14">14</a>  <em class="comment"> * Unless required by applicable law or agreed to in writing,</em>
<a name="15" href="#15">15</a>  <em class="comment"> * software distributed under the License is distributed on an</em>
<a name="16" href="#16">16</a>  <em class="comment"> * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY</em>
<a name="17" href="#17">17</a>  <em class="comment"> * KIND, either express or implied.  See the License for the</em>
<a name="18" href="#18">18</a>  <em class="comment"> * specific language governing permissions and limitations</em>
<a name="19" href="#19">19</a>  <em class="comment"> * under the License.</em>
<a name="20" href="#20">20</a>  <em class="comment"> */</em>
<a name="21" href="#21">21</a>  
<a name="22" href="#22">22</a>  <strong>import</strong> java.math.BigDecimal;
<a name="23" href="#23">23</a>  <strong>import</strong> java.sql.Connection;
<a name="24" href="#24">24</a>  <strong>import</strong> java.sql.ResultSet;
<a name="25" href="#25">25</a>  <strong>import</strong> java.sql.Statement;
<a name="26" href="#26">26</a>  <strong>import</strong> java.util.ArrayList;
<a name="27" href="#27">27</a>  <strong>import</strong> java.util.Hashtable;
<a name="28" href="#28">28</a>  <strong>import</strong> java.util.Iterator;
<a name="29" href="#29">29</a>  <strong>import</strong> java.util.List;
<a name="30" href="#30">30</a>  
<a name="31" href="#31">31</a>  <strong>import</strong> org.apache.commons.configuration.Configuration;
<a name="32" href="#32">32</a>  <strong>import</strong> org.apache.commons.logging.Log;
<a name="33" href="#33">33</a>  <strong>import</strong> org.apache.commons.logging.LogFactory;
<a name="34" href="#34">34</a>  <strong>import</strong> org.apache.torque.Database;
<a name="35" href="#35">35</a>  <strong>import</strong> org.apache.torque.Torque;
<a name="36" href="#36">36</a>  <strong>import</strong> org.apache.torque.TorqueException;
<a name="37" href="#37">37</a>  <strong>import</strong> org.apache.torque.map.TableMap;
<a name="38" href="#38">38</a>  <strong>import</strong> org.apache.torque.util.Transaction;
<a name="39" href="#39">39</a>  
<a name="40" href="#40">40</a>  <em class="comment">//!!</em>
<a name="41" href="#41">41</a>  <em class="comment">// NOTE:</em>
<a name="42" href="#42">42</a>  <em class="comment">// It would be nice to decouple this from</em>
<a name="43" href="#43">43</a>  <em class="comment">// Torque. This is a great stand-alone utility.</em>
<a name="44" href="#44">44</a>  
<a name="45" href="#45">45</a>  <em>/**<em>*</em></em>
<a name="46" href="#46">46</a>  <em> * This method of ID generation is used to ensure that code is</em>
<a name="47" href="#47">47</a>  <em> * more database independent.  For example, MySQL has an auto-increment</em>
<a name="48" href="#48">48</a>  <em> * feature while Oracle uses sequences.  It caches several ids to</em>
<a name="49" href="#49">49</a>  <em> * avoid needing a Connection for every request.</em>
<a name="50" href="#50">50</a>  <em> *</em>
<a name="51" href="#51">51</a>  <em> * This class uses the table ID_TABLE defined in</em>
<a name="52" href="#52">52</a>  <em> * conf/master/id-table-schema.xml.  The columns in ID_TABLE are used as</em>
<a name="53" href="#53">53</a>  <em> * follows:&lt;br></em>
<a name="54" href="#54">54</a>  <em> *</em>
<a name="55" href="#55">55</a>  <em> * ID_TABLE_ID - The PK for this row (any unique int).&lt;br></em>
<a name="56" href="#56">56</a>  <em> * TABLE_NAME - The name of the table you want ids for.&lt;br></em>
<a name="57" href="#57">57</a>  <em> * NEXT_ID - The next id returned by IDBroker when it queries the</em>
<a name="58" href="#58">58</a>  <em> *           database (not when it returns an id from memory).&lt;br></em>
<a name="59" href="#59">59</a>  <em> * QUANTITY - The number of ids that IDBroker will cache in memory.&lt;br></em>
<a name="60" href="#60">60</a>  <em> * &lt;p></em>
<a name="61" href="#61">61</a>  <em> * Use this class like this:</em>
<a name="62" href="#62">62</a>  <em> * &lt;pre></em>
<a name="63" href="#63">63</a>  <em> * int id = dbMap.getIDBroker().getNextIdAsInt(null, "TABLE_NAME");</em>
<a name="64" href="#64">64</a>  <em> *  - or -</em>
<a name="65" href="#65">65</a>  <em> * BigDecimal[] ids = ((IDBroker)dbMap.getIDBroker())</em>
<a name="66" href="#66">66</a>  <em> *     .getNextIds("TABLE_NAME", numOfIdsToReturn);</em>
<a name="67" href="#67">67</a>  <em> * &lt;/pre></em>
<a name="68" href="#68">68</a>  <em> *</em>
<a name="69" href="#69">69</a>  <em> * NOTE: When the ID_TABLE must be updated we must ensure that</em>
<a name="70" href="#70">70</a>  <em> * IDBroker objects running in different JVMs do not overwrite each</em>
<a name="71" href="#71">71</a>  <em> * other.  This is accomplished using using the transactional support</em>
<a name="72" href="#72">72</a>  <em> * occuring in some databases.  Using this class with a database that</em>
<a name="73" href="#73">73</a>  <em> * does not support transactions should be limited to a single JVM.</em>
<a name="74" href="#74">74</a>  <em> *</em>
<a name="75" href="#75">75</a>  <em> * @author &lt;a href="<a href="mailto:frank.kim@clearink.com" target="alexandria_uri">mailto:frank.kim@clearink.com</a>">Frank Y. Kim&lt;/a></em>
<a name="76" href="#76">76</a>  <em> * @author &lt;a href="<a href="mailto:jmcnally@collab.net" target="alexandria_uri">mailto:jmcnally@collab.net</a>">John D. McNally&lt;/a></em>
<a name="77" href="#77">77</a>  <em> * @author &lt;a href="<a href="mailto:hps@intermeta.de" target="alexandria_uri">mailto:hps@intermeta.de</a>">Henning P. Schmiedehausen&lt;/a></em>
<a name="78" href="#78">78</a>  <em> * @version $Id: IDBroker.java 552333 2007-07-01 16:24:19Z tv $</em>
<a name="79" href="#79">79</a>  <em> */</em>
<a name="80" href="#80">80</a>  <strong>public</strong> <strong>class</strong> <a href="../../../../org/apache/torque/oid/IDBroker.html">IDBroker</a> implements Runnable, <a href="../../../../org/apache/torque/oid/IdGenerator.html">IdGenerator</a>
<a name="81" href="#81">81</a>  {
<a name="82" href="#82">82</a>      <em>/**<em>* Name of the ID_TABLE = ID_TABLE */</em></em>
<a name="83" href="#83">83</a>      <strong>public</strong> <strong>static</strong> <strong>final</strong> String ID_TABLE = <span class="string">"ID_TABLE"</span>;
<a name="84" href="#84">84</a>  
<a name="85" href="#85">85</a>      <em>/**<em>* Table_Name column name */</em></em>
<a name="86" href="#86">86</a>      <strong>public</strong> <strong>static</strong> <strong>final</strong> String COL_TABLE_NAME = <span class="string">"TABLE_NAME"</span>;
<a name="87" href="#87">87</a>  
<a name="88" href="#88">88</a>      <em>/**<em>* Fully qualified Table_Name column name */</em></em>
<a name="89" href="#89">89</a>      <strong>public</strong> <strong>static</strong> <strong>final</strong> String TABLE_NAME = ID_TABLE + <span class="string">"."</span> + COL_TABLE_NAME;
<a name="90" href="#90">90</a>  
<a name="91" href="#91">91</a>      <em>/**<em>* ID column name */</em></em>
<a name="92" href="#92">92</a>      <strong>public</strong> <strong>static</strong> <strong>final</strong> String COL_TABLE_ID = <span class="string">"ID_TABLE_ID"</span>;
<a name="93" href="#93">93</a>  
<a name="94" href="#94">94</a>      <em>/**<em>* Fully qualified ID column name */</em></em>
<a name="95" href="#95">95</a>      <strong>public</strong> <strong>static</strong> <strong>final</strong> String TABLE_ID = ID_TABLE + <span class="string">"."</span> + COL_TABLE_ID;
<a name="96" href="#96">96</a>  
<a name="97" href="#97">97</a>      <em>/**<em>* Next_ID column name */</em></em>
<a name="98" href="#98">98</a>      <strong>public</strong> <strong>static</strong> <strong>final</strong> String COL_NEXT_ID = <span class="string">"NEXT_ID"</span>;
<a name="99" href="#99">99</a>  
<a name="100" href="#100">100</a>     <em>/**<em>* Fully qualified Next_ID column name */</em></em>
<a name="101" href="#101">101</a>     <strong>public</strong> <strong>static</strong> <strong>final</strong> String NEXT_ID = ID_TABLE + <span class="string">"."</span> + COL_NEXT_ID;
<a name="102" href="#102">102</a> 
<a name="103" href="#103">103</a>     <em>/**<em>* Quantity column name */</em></em>
<a name="104" href="#104">104</a>     <strong>public</strong> <strong>static</strong> <strong>final</strong> String COL_QUANTITY = <span class="string">"QUANTITY"</span>;
<a name="105" href="#105">105</a> 
<a name="106" href="#106">106</a>     <em>/**<em>* Fully qualified Quantity column name */</em></em>
<a name="107" href="#107">107</a>     <strong>public</strong> <strong>static</strong> <strong>final</strong> String QUANTITY = ID_TABLE + <span class="string">"."</span> + COL_QUANTITY;
<a name="108" href="#108">108</a> 
<a name="109" href="#109">109</a>     <em>/**<em>* the name of the database in which this IdBroker is running. */</em></em>
<a name="110" href="#110">110</a>     <strong>private</strong> String databaseName;
<a name="111" href="#111">111</a> 
<a name="112" href="#112">112</a>     <em>/**<em>*</em></em>
<a name="113" href="#113">113</a> <em>     * The default size of the per-table meta data &lt;code>Hashtable&lt;/code></em>
<a name="114" href="#114">114</a> <em>     * objects.</em>
<a name="115" href="#115">115</a> <em>     */</em>
<a name="116" href="#116">116</a>     <strong>private</strong> <strong>static</strong> <strong>final</strong> <strong>int</strong> DEFAULT_SIZE = 40;
<a name="117" href="#117">117</a> 
<a name="118" href="#118">118</a>     <em>/**<em>*</em></em>
<a name="119" href="#119">119</a> <em>     * The cached IDs for each table.</em>
<a name="120" href="#120">120</a> <em>     *</em>
<a name="121" href="#121">121</a> <em>     * Key: String table name.</em>
<a name="122" href="#122">122</a> <em>     * Value: List of Integer IDs.</em>
<a name="123" href="#123">123</a> <em>     */</em>
<a name="124" href="#124">124</a>     <strong>private</strong> Hashtable ids = <strong>new</strong> Hashtable(DEFAULT_SIZE);
<a name="125" href="#125">125</a> 
<a name="126" href="#126">126</a>     <em>/**<em>*</em></em>
<a name="127" href="#127">127</a> <em>     * The quantity of ids to grab for each table.</em>
<a name="128" href="#128">128</a> <em>     *</em>
<a name="129" href="#129">129</a> <em>     * Key: String table name.</em>
<a name="130" href="#130">130</a> <em>     * Value: Integer quantity.</em>
<a name="131" href="#131">131</a> <em>     */</em>
<a name="132" href="#132">132</a>     <strong>private</strong> Hashtable quantityStore = <strong>new</strong> Hashtable(DEFAULT_SIZE);
<a name="133" href="#133">133</a> 
<a name="134" href="#134">134</a>     <em>/**<em>*</em></em>
<a name="135" href="#135">135</a> <em>     * The last time this IDBroker queried the database for ids.</em>
<a name="136" href="#136">136</a> <em>     *</em>
<a name="137" href="#137">137</a> <em>     * Key: String table name.</em>
<a name="138" href="#138">138</a> <em>     * Value: Date of last id request.</em>
<a name="139" href="#139">139</a> <em>     */</em>
<a name="140" href="#140">140</a>     <strong>private</strong> Hashtable lastQueryTime = <strong>new</strong> Hashtable(DEFAULT_SIZE);
<a name="141" href="#141">141</a> 
<a name="142" href="#142">142</a>     <em>/**<em>*</em></em>
<a name="143" href="#143">143</a> <em>     * Amount of time for the thread to sleep</em>
<a name="144" href="#144">144</a> <em>     */</em>
<a name="145" href="#145">145</a>     <strong>private</strong> <strong>static</strong> <strong>final</strong> <strong>int</strong> SLEEP_PERIOD = 60000;
<a name="146" href="#146">146</a> 
<a name="147" href="#147">147</a>     <em>/**<em>*</em></em>
<a name="148" href="#148">148</a> <em>     * The safety Margin</em>
<a name="149" href="#149">149</a> <em>     */</em>
<a name="150" href="#150">150</a>     <strong>private</strong> <strong>static</strong> <strong>final</strong> <strong>float</strong> SAFETY_MARGIN = 1.2f;
<a name="151" href="#151">151</a> 
<a name="152" href="#152">152</a>     <em>/**<em>*</em></em>
<a name="153" href="#153">153</a> <em>     * The houseKeeperThread thread</em>
<a name="154" href="#154">154</a> <em>     */</em>
<a name="155" href="#155">155</a>     <strong>private</strong> Thread houseKeeperThread = <strong>null</strong>;
<a name="156" href="#156">156</a> 
<a name="157" href="#157">157</a>     <em>/**<em>*</em></em>
<a name="158" href="#158">158</a> <em>     * Are transactions supported?</em>
<a name="159" href="#159">159</a> <em>     */</em>
<a name="160" href="#160">160</a>     <strong>private</strong> <strong>boolean</strong> transactionsSupported = false;
<a name="161" href="#161">161</a> 
<a name="162" href="#162">162</a>     <em>/**<em>*</em></em>
<a name="163" href="#163">163</a> <em>     * The value of ONE!</em>
<a name="164" href="#164">164</a> <em>     */</em>
<a name="165" href="#165">165</a>     <strong>private</strong> <strong>static</strong> <strong>final</strong> BigDecimal ONE = <strong>new</strong> BigDecimal(<span class="string">"1"</span>);
<a name="166" href="#166">166</a> 
<a name="167" href="#167">167</a>     <em>/**<em>* the configuration */</em></em>
<a name="168" href="#168">168</a>     <strong>private</strong> Configuration configuration;
<a name="169" href="#169">169</a> 
<a name="170" href="#170">170</a>     <em>/**<em>* property name */</em></em>
<a name="171" href="#171">171</a>     <strong>private</strong> <strong>static</strong> <strong>final</strong> String DB_IDBROKER_CLEVERQUANTITY =
<a name="172" href="#172">172</a>         <span class="string">"idbroker.clever.quantity"</span>;
<a name="173" href="#173">173</a> 
<a name="174" href="#174">174</a>     <em>/**<em>* property name */</em></em>
<a name="175" href="#175">175</a>     <strong>private</strong> <strong>static</strong> <strong>final</strong> String DB_IDBROKER_PREFETCH =
<a name="176" href="#176">176</a>         <span class="string">"idbroker.prefetch"</span>;
<a name="177" href="#177">177</a> 
<a name="178" href="#178">178</a>     <em>/**<em>* property name */</em></em>
<a name="179" href="#179">179</a>     <strong>private</strong> <strong>static</strong> <strong>final</strong> String DB_IDBROKER_USENEWCONNECTION =
<a name="180" href="#180">180</a>         <span class="string">"idbroker.usenewconnection"</span>;
<a name="181" href="#181">181</a> 
<a name="182" href="#182">182</a>     <em>/**<em>* the log */</em></em>
<a name="183" href="#183">183</a>     <strong>private</strong> Log log = LogFactory.getLog(IDBroker.<strong>class</strong>);
<a name="184" href="#184">184</a> 
<a name="185" href="#185">185</a>     <em>/**<em>*</em></em>
<a name="186" href="#186">186</a> <em>     * constructs an IdBroker for the given Database.</em>
<a name="187" href="#187">187</a> <em>     * @param database the database where this IdBroker is running in.</em>
<a name="188" href="#188">188</a> <em>     */</em>
<a name="189" href="#189">189</a>     <strong>public</strong> <a href="../../../../org/apache/torque/oid/IDBroker.html">IDBroker</a>(<a href="../../../../org/apache/torque/Database.html">Database</a> database)
<a name="190" href="#190">190</a>     {
<a name="191" href="#191">191</a>         <strong>this</strong>(database.getName());
<a name="192" href="#192">192</a>     }
<a name="193" href="#193">193</a> 
<a name="194" href="#194">194</a>     <em>/**<em>*</em></em>
<a name="195" href="#195">195</a> <em>     * Creates an IDBroker for the ID table.</em>
<a name="196" href="#196">196</a> <em>     *</em>
<a name="197" href="#197">197</a> <em>     * @param tMap A TableMap.</em>
<a name="198" href="#198">198</a> <em>     * @deprecated Use IDBroker(DatabaseInfo) instead. Will be removed</em>
<a name="199" href="#199">199</a> <em>     *             in a future version of Torque.</em>
<a name="200" href="#200">200</a> <em>     */</em>
<a name="201" href="#201">201</a>     <strong>public</strong> <a href="../../../../org/apache/torque/oid/IDBroker.html">IDBroker</a>(<a href="../../../../org/apache/torque/map/TableMap.html">TableMap</a> tMap)
<a name="202" href="#202">202</a>     {
<a name="203" href="#203">203</a>         <strong>this</strong>(tMap.getDatabaseMap().getName());
<a name="204" href="#204">204</a>     }
<a name="205" href="#205">205</a> 
<a name="206" href="#206">206</a>     <em>/**<em>*</em></em>
<a name="207" href="#207">207</a> <em>     * Constructor.</em>
<a name="208" href="#208">208</a> <em>     * Provided as long as both Constructors, IDBroker(DatabaseInfo) and</em>
<a name="209" href="#209">209</a> <em>     * IDBroker(TableMap), are around.</em>
<a name="210" href="#210">210</a> <em>     * @param databaseName the name of the database for which this IdBroker</em>
<a name="211" href="#211">211</a> <em>     *        provides Ids.</em>
<a name="212" href="#212">212</a> <em>     */</em>
<a name="213" href="#213">213</a>     <strong>private</strong> <a href="../../../../org/apache/torque/oid/IDBroker.html">IDBroker</a>(String databaseName)
<a name="214" href="#214">214</a>     {
<a name="215" href="#215">215</a>         <strong>this</strong>.databaseName = databaseName;
<a name="216" href="#216">216</a>         configuration = Torque.getConfiguration();
<a name="217" href="#217">217</a> 
<a name="218" href="#218">218</a>         <em class="comment">// Start the housekeeper thread only if prefetch has not been disabled</em>
<a name="219" href="#219">219</a>         <strong>if</strong> (configuration.getBoolean(DB_IDBROKER_PREFETCH, <strong>true</strong>))
<a name="220" href="#220">220</a>         {
<a name="221" href="#221">221</a>             houseKeeperThread = <strong>new</strong> Thread(<strong>this</strong>);
<a name="222" href="#222">222</a>             <em class="comment">// Indicate that this is a system thread. JVM will quit only when</em>
<a name="223" href="#223">223</a>             <em class="comment">// there are no more active user threads. Settings threads spawned</em>
<a name="224" href="#224">224</a>             <em class="comment">// internally by Torque as daemons allows commandline applications</em>
<a name="225" href="#225">225</a>             <em class="comment">// using Torque terminate in an orderly manner.</em>
<a name="226" href="#226">226</a>             houseKeeperThread.setDaemon(<strong>true</strong>);
<a name="227" href="#227">227</a>             houseKeeperThread.setName(<span class="string">"Torque - ID Broker thread"</span>);
<a name="228" href="#228">228</a>             houseKeeperThread.start();
<a name="229" href="#229">229</a>         }
<a name="230" href="#230">230</a> 
<a name="231" href="#231">231</a>         <em class="comment">// Check for Transaction support.  Give warning message if</em>
<a name="232" href="#232">232</a>         <em class="comment">// IDBroker is being used with a database that does not</em>
<a name="233" href="#233">233</a>         <em class="comment">// support transactions.</em>
<a name="234" href="#234">234</a>         Connection dbCon = <strong>null</strong>;
<a name="235" href="#235">235</a>         <strong>try</strong>
<a name="236" href="#236">236</a>         {
<a name="237" href="#237">237</a>             dbCon = Torque.getConnection(databaseName);
<a name="238" href="#238">238</a>         }
<a name="239" href="#239">239</a>         <strong>catch</strong> (Throwable t)
<a name="240" href="#240">240</a>         {
<a name="241" href="#241">241</a>             log.error(<span class="string">"Could not open a connection to the database "</span>
<a name="242" href="#242">242</a>                     + databaseName,
<a name="243" href="#243">243</a>                     t);
<a name="244" href="#244">244</a>             transactionsSupported = false;
<a name="245" href="#245">245</a>         }
<a name="246" href="#246">246</a>         <strong>try</strong>
<a name="247" href="#247">247</a>         {
<a name="248" href="#248">248</a>             transactionsSupported = dbCon.getMetaData().supportsTransactions();
<a name="249" href="#249">249</a>         }
<a name="250" href="#250">250</a>         <strong>catch</strong> (Exception e)
<a name="251" href="#251">251</a>         {
<a name="252" href="#252">252</a>             log.warn(<span class="string">"Could not read from connection Metadata"</span>
<a name="253" href="#253">253</a>                     + <span class="string">" whether transactions are supported for the database "</span>
<a name="254" href="#254">254</a>                     + databaseName,
<a name="255" href="#255">255</a>                     e);
<a name="256" href="#256">256</a>             transactionsSupported = false;
<a name="257" href="#257">257</a>         }
<a name="258" href="#258">258</a>         <strong>finally</strong>
<a name="259" href="#259">259</a>         {
<a name="260" href="#260">260</a>             <strong>try</strong>
<a name="261" href="#261">261</a>             {
<a name="262" href="#262">262</a>                 <em class="comment">// Return the connection to the pool.</em>
<a name="263" href="#263">263</a>                 dbCon.close();
<a name="264" href="#264">264</a>             }
<a name="265" href="#265">265</a>             <strong>catch</strong> (Exception e)
<a name="266" href="#266">266</a>             {
<a name="267" href="#267">267</a>                 log.warn(<span class="string">"Could not close the connection which was used "</span>
<a name="268" href="#268">268</a>                         + <span class="string">"for testing whether transactions are supported"</span>,
<a name="269" href="#269">269</a>                         e);
<a name="270" href="#270">270</a>             }
<a name="271" href="#271">271</a>         }
<a name="272" href="#272">272</a>         <strong>if</strong> (!transactionsSupported)
<a name="273" href="#273">273</a>         {
<a name="274" href="#274">274</a>             log.warn(<span class="string">"IDBroker is being used with db '"</span> + databaseName
<a name="275" href="#275">275</a>                     + <span class="string">"', which does not support transactions. IDBroker "</span>
<a name="276" href="#276">276</a>                     + <span class="string">"attempts to use transactions to limit the possibility "</span>
<a name="277" href="#277">277</a>                     + <span class="string">"of duplicate key generation.  Without transactions, "</span>
<a name="278" href="#278">278</a>                     + <span class="string">"duplicate key generation is possible if multiple JVMs "</span>
<a name="279" href="#279">279</a>                     + <span class="string">"are used or other means are used to write to the "</span>
<a name="280" href="#280">280</a>                     + <span class="string">"database."</span>);
<a name="281" href="#281">281</a>         }
<a name="282" href="#282">282</a>     }
<a name="283" href="#283">283</a> 
<a name="284" href="#284">284</a>     <em>/**<em>*</em></em>
<a name="285" href="#285">285</a> <em>     * Set the configuration</em>
<a name="286" href="#286">286</a> <em>     *</em>
<a name="287" href="#287">287</a> <em>     * @param configuration the configuration</em>
<a name="288" href="#288">288</a> <em>     */</em>
<a name="289" href="#289">289</a>     <strong>public</strong> <strong>void</strong> setConfiguration(Configuration configuration)
<a name="290" href="#290">290</a>     {
<a name="291" href="#291">291</a>         <strong>this</strong>.configuration = configuration;
<a name="292" href="#292">292</a>     }
<a name="293" href="#293">293</a> 
<a name="294" href="#294">294</a>     <em>/**<em>*</em></em>
<a name="295" href="#295">295</a> <em>     * Returns an id as a primitive int.  Note this method does not</em>
<a name="296" href="#296">296</a> <em>     * require a Connection, it just implements the KeyGenerator</em>
<a name="297" href="#297">297</a> <em>     * interface.  if a Connection is needed one will be requested.</em>
<a name="298" href="#298">298</a> <em>     * To force the use of the passed in connection set the configuration</em>
<a name="299" href="#299">299</a> <em>     * property torque.idbroker.usenewconnection = false</em>
<a name="300" href="#300">300</a> <em>     *</em>
<a name="301" href="#301">301</a> <em>     * @param connection A Connection.</em>
<a name="302" href="#302">302</a> <em>     * @param tableName an Object that contains additional info.</em>
<a name="303" href="#303">303</a> <em>     * @return An int with the value for the id.</em>
<a name="304" href="#304">304</a> <em>     * @exception Exception Database error.</em>
<a name="305" href="#305">305</a> <em>     */</em>
<a name="306" href="#306">306</a>     <strong>public</strong> <strong>int</strong> getIdAsInt(Connection connection, Object tableName)
<a name="307" href="#307">307</a>         throws Exception
<a name="308" href="#308">308</a>     {
<a name="309" href="#309">309</a>         <strong>return</strong> getIdAsBigDecimal(connection, tableName).intValue();
<a name="310" href="#310">310</a>     }
<a name="311" href="#311">311</a> 
<a name="312" href="#312">312</a> 
<a name="313" href="#313">313</a>     <em>/**<em>*</em></em>
<a name="314" href="#314">314</a> <em>     * Returns an id as a primitive long. Note this method does not</em>
<a name="315" href="#315">315</a> <em>     * require a Connection, it just implements the KeyGenerator</em>
<a name="316" href="#316">316</a> <em>     * interface.  if a Connection is needed one will be requested.</em>
<a name="317" href="#317">317</a> <em>     * To force the use of the passed in connection set the configuration</em>
<a name="318" href="#318">318</a> <em>     * property torque.idbroker.usenewconnection = false</em>
<a name="319" href="#319">319</a> <em>     *</em>
<a name="320" href="#320">320</a> <em>     * @param connection A Connection.</em>
<a name="321" href="#321">321</a> <em>     * @param tableName a String that identifies a table.</em>
<a name="322" href="#322">322</a> <em>     * @return A long with the value for the id.</em>
<a name="323" href="#323">323</a> <em>     * @exception Exception Database error.</em>
<a name="324" href="#324">324</a> <em>     */</em>
<a name="325" href="#325">325</a>     <strong>public</strong> <strong>long</strong> getIdAsLong(Connection connection, Object tableName)
<a name="326" href="#326">326</a>         throws Exception
<a name="327" href="#327">327</a>     {
<a name="328" href="#328">328</a>         <strong>return</strong> getIdAsBigDecimal(connection, tableName).longValue();
<a name="329" href="#329">329</a>     }
<a name="330" href="#330">330</a> 
<a name="331" href="#331">331</a>     <em>/**<em>*</em></em>
<a name="332" href="#332">332</a> <em>     * Returns an id as a BigDecimal. Note this method does not</em>
<a name="333" href="#333">333</a> <em>     * require a Connection, it just implements the KeyGenerator</em>
<a name="334" href="#334">334</a> <em>     * interface.  if a Connection is needed one will be requested.</em>
<a name="335" href="#335">335</a> <em>     * To force the use of the passed in connection set the configuration</em>
<a name="336" href="#336">336</a> <em>     * property torque.idbroker.usenewconnection = false</em>
<a name="337" href="#337">337</a> <em>     *</em>
<a name="338" href="#338">338</a> <em>     * @param connection A Connection.</em>
<a name="339" href="#339">339</a> <em>     * @param tableName a String that identifies a table..</em>
<a name="340" href="#340">340</a> <em>     * @return A BigDecimal id.</em>
<a name="341" href="#341">341</a> <em>     * @exception Exception Database error.</em>
<a name="342" href="#342">342</a> <em>     */</em>
<a name="343" href="#343">343</a>     <strong>public</strong> BigDecimal getIdAsBigDecimal(Connection connection,
<a name="344" href="#344">344</a>                                         Object tableName)
<a name="345" href="#345">345</a>         throws Exception
<a name="346" href="#346">346</a>     {
<a name="347" href="#347">347</a>         BigDecimal[] id = getNextIds((String) tableName, 1, connection);
<a name="348" href="#348">348</a>         <strong>return</strong> id[0];
<a name="349" href="#349">349</a>     }
<a name="350" href="#350">350</a> 
<a name="351" href="#351">351</a>     <em>/**<em>*</em></em>
<a name="352" href="#352">352</a> <em>     * Returns an id as a String. Note this method does not</em>
<a name="353" href="#353">353</a> <em>     * require a Connection, it just implements the KeyGenerator</em>
<a name="354" href="#354">354</a> <em>     * interface.  if a Connection is needed one will be requested.</em>
<a name="355" href="#355">355</a> <em>     * To force the use of the passed in connection set the configuration</em>
<a name="356" href="#356">356</a> <em>     * property torque.idbroker.usenewconnection = false</em>
<a name="357" href="#357">357</a> <em>     *</em>
<a name="358" href="#358">358</a> <em>     * @param connection A Connection should be null.</em>
<a name="359" href="#359">359</a> <em>     * @param tableName a String that identifies a table.</em>
<a name="360" href="#360">360</a> <em>     * @return A String id</em>
<a name="361" href="#361">361</a> <em>     * @exception Exception Database error.</em>
<a name="362" href="#362">362</a> <em>     */</em>
<a name="363" href="#363">363</a>     <strong>public</strong> String getIdAsString(Connection connection, Object tableName)
<a name="364" href="#364">364</a>         throws Exception
<a name="365" href="#365">365</a>     {
<a name="366" href="#366">366</a>         <strong>return</strong> getIdAsBigDecimal(connection, tableName).toString();
<a name="367" href="#367">367</a>     }
<a name="368" href="#368">368</a> 
<a name="369" href="#369">369</a> 
<a name="370" href="#370">370</a>     <em>/**<em>*</em></em>
<a name="371" href="#371">371</a> <em>     * A flag to determine the timing of the id generation     *</em>
<a name="372" href="#372">372</a> <em>     * @return a &lt;code>boolean&lt;/code> value</em>
<a name="373" href="#373">373</a> <em>     */</em>
<a name="374" href="#374">374</a>     <strong>public</strong> <strong>boolean</strong> isPriorToInsert()
<a name="375" href="#375">375</a>     {
<a name="376" href="#376">376</a>         <strong>return</strong> <strong>true</strong>;
<a name="377" href="#377">377</a>     }
<a name="378" href="#378">378</a> 
<a name="379" href="#379">379</a>     <em>/**<em>*</em></em>
<a name="380" href="#380">380</a> <em>     * A flag to determine the timing of the id generation</em>
<a name="381" href="#381">381</a> <em>     *</em>
<a name="382" href="#382">382</a> <em>     * @return a &lt;code>boolean&lt;/code> value</em>
<a name="383" href="#383">383</a> <em>     */</em>
<a name="384" href="#384">384</a>     <strong>public</strong> <strong>boolean</strong> isPostInsert()
<a name="385" href="#385">385</a>     {
<a name="386" href="#386">386</a>         <strong>return</strong> false;
<a name="387" href="#387">387</a>     }
<a name="388" href="#388">388</a> 
<a name="389" href="#389">389</a>     <em>/**<em>*</em></em>
<a name="390" href="#390">390</a> <em>     * A flag to determine whether a Connection is required to</em>
<a name="391" href="#391">391</a> <em>     * generate an id.</em>
<a name="392" href="#392">392</a> <em>     *</em>
<a name="393" href="#393">393</a> <em>     * @return a &lt;code>boolean&lt;/code> value</em>
<a name="394" href="#394">394</a> <em>     */</em>
<a name="395" href="#395">395</a>     <strong>public</strong> <strong>boolean</strong> isConnectionRequired()
<a name="396" href="#396">396</a>     {
<a name="397" href="#397">397</a>         <strong>return</strong> false;
<a name="398" href="#398">398</a>     }
<a name="399" href="#399">399</a> 
<a name="400" href="#400">400</a>     <em>/**<em>*</em></em>
<a name="401" href="#401">401</a> <em>     * This method returns x number of ids for the given table.</em>
<a name="402" href="#402">402</a> <em>     *</em>
<a name="403" href="#403">403</a> <em>     * @param tableName The name of the table for which we want an id.</em>
<a name="404" href="#404">404</a> <em>     * @param numOfIdsToReturn The desired number of ids.</em>
<a name="405" href="#405">405</a> <em>     * @return A BigDecimal.</em>
<a name="406" href="#406">406</a> <em>     * @exception Exception Database error.</em>
<a name="407" href="#407">407</a> <em>     */</em>
<a name="408" href="#408">408</a>     <strong>public</strong> <strong>synchronized</strong> BigDecimal[] getNextIds(String tableName,
<a name="409" href="#409">409</a>                                                 <strong>int</strong> numOfIdsToReturn)
<a name="410" href="#410">410</a>         throws Exception
<a name="411" href="#411">411</a>     {
<a name="412" href="#412">412</a>         <strong>return</strong> getNextIds(tableName, numOfIdsToReturn, <strong>null</strong>);
<a name="413" href="#413">413</a>     }
<a name="414" href="#414">414</a> 
<a name="415" href="#415">415</a>     <em>/**<em>*</em></em>
<a name="416" href="#416">416</a> <em>     * This method returns x number of ids for the given table.</em>
<a name="417" href="#417">417</a> <em>     * Note this method does not require a Connection.</em>
<a name="418" href="#418">418</a> <em>     * If a Connection is needed one will be requested.</em>
<a name="419" href="#419">419</a> <em>     * To force the use of the passed in connection set the configuration</em>
<a name="420" href="#420">420</a> <em>     * property torque.idbroker.usenewconnection = false</em>
<a name="421" href="#421">421</a> <em>     *</em>
<a name="422" href="#422">422</a> <em>     * @param tableName The name of the table for which we want an id.</em>
<a name="423" href="#423">423</a> <em>     * @param numOfIdsToReturn The desired number of ids.</em>
<a name="424" href="#424">424</a> <em>     * @param connection A Connection.</em>
<a name="425" href="#425">425</a> <em>     * @return A BigDecimal.</em>
<a name="426" href="#426">426</a> <em>     * @exception Exception Database error.</em>
<a name="427" href="#427">427</a> <em>     */</em>
<a name="428" href="#428">428</a>     <strong>public</strong> <strong>synchronized</strong> BigDecimal[] getNextIds(String tableName,
<a name="429" href="#429">429</a>                                                 <strong>int</strong> numOfIdsToReturn,
<a name="430" href="#430">430</a>                                                 Connection connection)
<a name="431" href="#431">431</a>         throws Exception
<a name="432" href="#432">432</a>     {
<a name="433" href="#433">433</a>         <strong>if</strong> (tableName == <strong>null</strong>)
<a name="434" href="#434">434</a>         {
<a name="435" href="#435">435</a>             <strong>throw</strong> <strong>new</strong> Exception(<span class="string">"getNextIds(): tableName == null"</span>);
<a name="436" href="#436">436</a>         }
<a name="437" href="#437">437</a> 
<a name="438" href="#438">438</a>         <em class="comment">// A note about the synchronization:  I (jmcnally) looked at</em>
<a name="439" href="#439">439</a>         <em class="comment">// the synchronized blocks to avoid thread issues that were</em>
<a name="440" href="#440">440</a>         <em class="comment">// being used in this and the storeId method.  I do not think</em>
<a name="441" href="#441">441</a>         <em class="comment">// they were being effective, so I synchronized the method.</em>
<a name="442" href="#442">442</a>         <em class="comment">// I have left the blocks that did exist commented in the code</em>
<a name="443" href="#443">443</a>         <em class="comment">// to make it easier for others to take a look, because it</em>
<a name="444" href="#444">444</a>         <em class="comment">// would be preferrable to avoid the synchronization on the</em>
<a name="445" href="#445">445</a>         <em class="comment">// method</em>
<a name="446" href="#446">446</a> 
<a name="447" href="#447">447</a>         List availableIds = (List) ids.get(tableName);
<a name="448" href="#448">448</a> 
<a name="449" href="#449">449</a>         <strong>if</strong> (availableIds == <strong>null</strong> || availableIds.size() &lt; numOfIdsToReturn)
<a name="450" href="#450">450</a>         {
<a name="451" href="#451">451</a>             <strong>if</strong> (availableIds == <strong>null</strong>)
<a name="452" href="#452">452</a>             {
<a name="453" href="#453">453</a>                 log.debug(<span class="string">"Forced id retrieval - no available list"</span>);
<a name="454" href="#454">454</a>             }
<a name="455" href="#455">455</a>             <strong>else</strong>
<a name="456" href="#456">456</a>             {
<a name="457" href="#457">457</a>                 log.debug(<span class="string">"Forced id retrieval - "</span> + availableIds.size());
<a name="458" href="#458">458</a>             }
<a name="459" href="#459">459</a>             storeIDs(tableName, <strong>true</strong>, connection);
<a name="460" href="#460">460</a>             availableIds = (List) ids.get(tableName);
<a name="461" href="#461">461</a>         }
<a name="462" href="#462">462</a> 
<a name="463" href="#463">463</a>         <strong>int</strong> size = availableIds.size() &lt; numOfIdsToReturn
<a name="464" href="#464">464</a>                 ? availableIds.size() : numOfIdsToReturn;
<a name="465" href="#465">465</a> 
<a name="466" href="#466">466</a>         BigDecimal[] results = <strong>new</strong> BigDecimal[size];
<a name="467" href="#467">467</a> 
<a name="468" href="#468">468</a>         <em class="comment">// We assume that availableIds will always come from the ids</em>
<a name="469" href="#469">469</a>         <em class="comment">// Hashtable and would therefore always be the same object for</em>
<a name="470" href="#470">470</a>         <em class="comment">// a specific table.</em>
<a name="471" href="#471">471</a>         <em class="comment">//        synchronized (availableIds)</em>
<a name="472" href="#472">472</a>         <em class="comment">//        {</em>
<a name="473" href="#473">473</a>         <strong>for</strong> (<strong>int</strong> i = size - 1; i >= 0; i--)
<a name="474" href="#474">474</a>         {
<a name="475" href="#475">475</a>             results[i] = (BigDecimal) availableIds.get(i);
<a name="476" href="#476">476</a>             availableIds.remove(i);
<a name="477" href="#477">477</a>         }
<a name="478" href="#478">478</a>         <em class="comment">//        }</em>
<a name="479" href="#479">479</a> 
<a name="480" href="#480">480</a>         <strong>return</strong> results;
<a name="481" href="#481">481</a>     }
<a name="482" href="#482">482</a> 
<a name="483" href="#483">483</a>     <em>/**<em>*</em></em>
<a name="484" href="#484">484</a> <em>     * @param tableName a &lt;code>String&lt;/code> value that is used to identify</em>
<a name="485" href="#485">485</a> <em>     * the row</em>
<a name="486" href="#486">486</a> <em>     * @return a &lt;code>boolean&lt;/code> value</em>
<a name="487" href="#487">487</a> <em>     * @exception TorqueException if a Torque error occurs.</em>
<a name="488" href="#488">488</a> <em>     * @exception Exception if another error occurs.</em>
<a name="489" href="#489">489</a> <em>     */</em>
<a name="490" href="#490">490</a>     <strong>public</strong> <strong>boolean</strong> exists(String tableName)
<a name="491" href="#491">491</a>         throws Exception
<a name="492" href="#492">492</a>     {
<a name="493" href="#493">493</a>         String query = <strong>new</strong> StringBuffer(100)
<a name="494" href="#494">494</a>             .append(<span class="string">"select "</span>)
<a name="495" href="#495">495</a>             .append(TABLE_NAME)
<a name="496" href="#496">496</a>             .append(<span class="string">" where "</span>)
<a name="497" href="#497">497</a>             .append(TABLE_NAME).append(<span class="string">"='"</span>).append(tableName).append('\'')
<a name="498" href="#498">498</a>             .toString();
<a name="499" href="#499">499</a> 
<a name="500" href="#500">500</a>         <strong>boolean</strong> exists = false;
<a name="501" href="#501">501</a>         Connection dbCon = <strong>null</strong>;
<a name="502" href="#502">502</a>         <strong>try</strong>
<a name="503" href="#503">503</a>         {
<a name="504" href="#504">504</a>             dbCon = Torque.getConnection(databaseName);
<a name="505" href="#505">505</a>             Statement statement = dbCon.createStatement();
<a name="506" href="#506">506</a>             ResultSet rs = statement.executeQuery(query);
<a name="507" href="#507">507</a>             exists = rs.next();
<a name="508" href="#508">508</a>             statement.close();
<a name="509" href="#509">509</a>         }
<a name="510" href="#510">510</a>         <strong>finally</strong>
<a name="511" href="#511">511</a>         {
<a name="512" href="#512">512</a>             <em class="comment">// Return the connection to the pool.</em>
<a name="513" href="#513">513</a>             <strong>try</strong>
<a name="514" href="#514">514</a>             {
<a name="515" href="#515">515</a>                 dbCon.close();
<a name="516" href="#516">516</a>             }
<a name="517" href="#517">517</a>             <strong>catch</strong> (Exception e)
<a name="518" href="#518">518</a>             {
<a name="519" href="#519">519</a>                 log.error(<span class="string">"Release of connection failed."</span>, e);
<a name="520" href="#520">520</a>             }
<a name="521" href="#521">521</a>         }
<a name="522" href="#522">522</a>         <strong>return</strong> exists;
<a name="523" href="#523">523</a>     }
<a name="524" href="#524">524</a> 
<a name="525" href="#525">525</a>     <em>/**<em>*</em></em>
<a name="526" href="#526">526</a> <em>     * A background thread that tries to ensure that when someone asks</em>
<a name="527" href="#527">527</a> <em>     * for ids, that there are already some loaded and that the</em>
<a name="528" href="#528">528</a> <em>     * database is not accessed.</em>
<a name="529" href="#529">529</a> <em>     */</em>
<a name="530" href="#530">530</a>     <strong>public</strong> <strong>void</strong> run()
<a name="531" href="#531">531</a>     {
<a name="532" href="#532">532</a>         log.debug(<span class="string">"IDBroker thread was started."</span>);
<a name="533" href="#533">533</a> 
<a name="534" href="#534">534</a>         Thread thisThread = Thread.currentThread();
<a name="535" href="#535">535</a>         <strong>while</strong> (houseKeeperThread == thisThread)
<a name="536" href="#536">536</a>         {
<a name="537" href="#537">537</a>             <strong>try</strong>
<a name="538" href="#538">538</a>             {
<a name="539" href="#539">539</a>                 Thread.sleep(SLEEP_PERIOD);
<a name="540" href="#540">540</a>             }
<a name="541" href="#541">541</a>             <strong>catch</strong> (InterruptedException exc)
<a name="542" href="#542">542</a>             {
<a name="543" href="#543">543</a>                 <em class="comment">// ignored</em>
<a name="544" href="#544">544</a>             }
<a name="545" href="#545">545</a> 
<a name="546" href="#546">546</a>             <em class="comment">// logger.info("IDBroker thread checking for more keys.");</em>
<a name="547" href="#547">547</a>             Iterator it = ids.keySet().iterator();
<a name="548" href="#548">548</a>             <strong>while</strong> (it.hasNext())
<a name="549" href="#549">549</a>             {
<a name="550" href="#550">550</a>                 String tableName = (String) it.next();
<a name="551" href="#551">551</a>                 <strong>if</strong> (log.isDebugEnabled())
<a name="552" href="#552">552</a>                 {
<a name="553" href="#553">553</a>                     log.debug(<span class="string">"IDBroker thread checking for more keys "</span>
<a name="554" href="#554">554</a>                             + <span class="string">"on table: "</span> + tableName);
<a name="555" href="#555">555</a>                 }
<a name="556" href="#556">556</a>                 List availableIds = (List) ids.get(tableName);
<a name="557" href="#557">557</a>                 <strong>int</strong> quantity = getQuantity(tableName, <strong>null</strong>).<strong>int</strong>Value();
<a name="558" href="#558">558</a>                 <strong>if</strong> (quantity > availableIds.size())
<a name="559" href="#559">559</a>                 {
<a name="560" href="#560">560</a>                     <strong>try</strong>
<a name="561" href="#561">561</a>                     {
<a name="562" href="#562">562</a>                         <em class="comment">// Second parameter is false because we don't</em>
<a name="563" href="#563">563</a>                         <em class="comment">// want the quantity to be adjusted for thread</em>
<a name="564" href="#564">564</a>                         <em class="comment">// calls.</em>
<a name="565" href="#565">565</a>                         storeIDs(tableName, false, <strong>null</strong>);
<a name="566" href="#566">566</a>                         <strong>if</strong> (log.isDebugEnabled())
<a name="567" href="#567">567</a>                         {
<a name="568" href="#568">568</a>                             log.debug(<span class="string">"Retrieved more ids for table: "</span> + tableName);
<a name="569" href="#569">569</a>                         }
<a name="570" href="#570">570</a>                     }
<a name="571" href="#571">571</a>                     <strong>catch</strong> (Exception exc)
<a name="572" href="#572">572</a>                     {
<a name="573" href="#573">573</a>                         log.error(<span class="string">"There was a problem getting new IDs "</span>
<a name="574" href="#574">574</a>                                      + <span class="string">"for table: "</span> + tableName, exc);
<a name="575" href="#575">575</a>                     }
<a name="576" href="#576">576</a>                 }
<a name="577" href="#577">577</a>             }
<a name="578" href="#578">578</a>         }
<a name="579" href="#579">579</a>         log.debug(<span class="string">"IDBroker thread finished."</span>);
<a name="580" href="#580">580</a>     }
<a name="581" href="#581">581</a> 
<a name="582" href="#582">582</a>     <em>/**<em>*</em></em>
<a name="583" href="#583">583</a> <em>     * Shuts down the IDBroker thread.</em>
<a name="584" href="#584">584</a> <em>     *</em>
<a name="585" href="#585">585</a> <em>     * Calling this method stops the thread that was started for this</em>
<a name="586" href="#586">586</a> <em>     * instance of the IDBroker. This method should be called during</em>
<a name="587" href="#587">587</a> <em>     * MapBroker Service shutdown.</em>
<a name="588" href="#588">588</a> <em>     */</em>
<a name="589" href="#589">589</a>     <strong>public</strong> <strong>void</strong> stop()
<a name="590" href="#590">590</a>     {
<a name="591" href="#591">591</a>         houseKeeperThread = <strong>null</strong>;
<a name="592" href="#592">592</a>     }
<a name="593" href="#593">593</a> 
<a name="594" href="#594">594</a>     <em>/**<em>*</em></em>
<a name="595" href="#595">595</a> <em>     * Check the frequency of retrieving new ids from the database.</em>
<a name="596" href="#596">596</a> <em>     * If the frequency is high then we increase the amount (i.e.</em>
<a name="597" href="#597">597</a> <em>     * quantity column) of ids retrieved on each access.  Tries to</em>
<a name="598" href="#598">598</a> <em>     * alter number of keys grabbed so that IDBroker retrieves a new</em>
<a name="599" href="#599">599</a> <em>     * set of ID's prior to their being needed.</em>
<a name="600" href="#600">600</a> <em>     *</em>
<a name="601" href="#601">601</a> <em>     * @param tableName The name of the table for which we want an id.</em>
<a name="602" href="#602">602</a> <em>     */</em>
<a name="603" href="#603">603</a>     <strong>private</strong> <strong>void</strong> checkTiming(String tableName)
<a name="604" href="#604">604</a>     {
<a name="605" href="#605">605</a>         <em class="comment">// Check if quantity changing is switched on.</em>
<a name="606" href="#606">606</a>         <em class="comment">// If prefetch is turned off, changing quantity does not make sense</em>
<a name="607" href="#607">607</a>         <strong>if</strong> (!configuration.getBoolean(DB_IDBROKER_CLEVERQUANTITY, <strong>true</strong>)
<a name="608" href="#608">608</a>             || !configuration.getBoolean(DB_IDBROKER_PREFETCH, <strong>true</strong>))
<a name="609" href="#609">609</a>         {
<a name="610" href="#610">610</a>             <strong>return</strong>;
<a name="611" href="#611">611</a>         }
<a name="612" href="#612">612</a> 
<a name="613" href="#613">613</a>         <em class="comment">// Get the last id request for this table.</em>
<a name="614" href="#614">614</a>         java.util.Date lastTime = (java.util.Date) lastQueryTime.get(tableName);
<a name="615" href="#615">615</a>         java.util.Date now = <strong>new</strong> java.util.Date();
<a name="616" href="#616">616</a> 
<a name="617" href="#617">617</a>         <strong>if</strong> (lastTime != <strong>null</strong>)
<a name="618" href="#618">618</a>         {
<a name="619" href="#619">619</a>             <strong>long</strong> thenLong = lastTime.getTime();
<a name="620" href="#620">620</a>             <strong>long</strong> nowLong = now.getTime();
<a name="621" href="#621">621</a>             <strong>int</strong> timeLapse = (<strong>int</strong>) (nowLong - thenLong);
<a name="622" href="#622">622</a>             <strong>if</strong> (timeLapse &lt; SLEEP_PERIOD &amp;&amp; timeLapse > 0)
<a name="623" href="#623">623</a>             {
<a name="624" href="#624">624</a>                 <strong>if</strong> (log.isDebugEnabled())
<a name="625" href="#625">625</a>                 {
<a name="626" href="#626">626</a>                     log.debug(<span class="string">"Unscheduled retrieval of more ids for table: "</span>
<a name="627" href="#627">627</a>                             + tableName);
<a name="628" href="#628">628</a>                 }
<a name="629" href="#629">629</a>                 <em class="comment">// Increase quantity, so that hopefully this does not</em>
<a name="630" href="#630">630</a>                 <em class="comment">// happen again.</em>
<a name="631" href="#631">631</a>                 <strong>float</strong> rate = getQuantity(tableName, <strong>null</strong>).<strong>float</strong>Value()
<a name="632" href="#632">632</a>                     / (<strong>float</strong>) timeLapse;
<a name="633" href="#633">633</a>                 quantityStore.put(tableName, <strong>new</strong> BigDecimal(
<a name="634" href="#634">634</a>                     Math.ceil(SLEEP_PERIOD * rate * SAFETY_MARGIN)));
<a name="635" href="#635">635</a>             }
<a name="636" href="#636">636</a>         }
<a name="637" href="#637">637</a>         lastQueryTime.put(tableName, now);
<a name="638" href="#638">638</a>     }
<a name="639" href="#639">639</a> 
<a name="640" href="#640">640</a>     <em>/**<em>*</em></em>
<a name="641" href="#641">641</a> <em>     * Grabs more ids from the id_table and stores it in the ids</em>
<a name="642" href="#642">642</a> <em>     * Hashtable.  If adjustQuantity is set to true the amount of id's</em>
<a name="643" href="#643">643</a> <em>     * retrieved for each call to storeIDs will be adjusted.</em>
<a name="644" href="#644">644</a> <em>     *</em>
<a name="645" href="#645">645</a> <em>     * @param tableName The name of the table for which we want an id.</em>
<a name="646" href="#646">646</a> <em>     * @param adjustQuantity True if amount should be adjusted.</em>
<a name="647" href="#647">647</a> <em>     * @param connection a Connection</em>
<a name="648" href="#648">648</a> <em>     * @exception Exception a generic exception.</em>
<a name="649" href="#649">649</a> <em>     */</em>
<a name="650" href="#650">650</a>     <strong>private</strong> <strong>synchronized</strong> <strong>void</strong> storeIDs(String tableName,
<a name="651" href="#651">651</a>                           <strong>boolean</strong> adjustQuantity,
<a name="652" href="#652">652</a>                           Connection connection)
<a name="653" href="#653">653</a>         throws Exception
<a name="654" href="#654">654</a>     {
<a name="655" href="#655">655</a>         BigDecimal nextId = <strong>null</strong>;
<a name="656" href="#656">656</a>         BigDecimal quantity = <strong>null</strong>;
<a name="657" href="#657">657</a> 
<a name="658" href="#658">658</a>         <em class="comment">// Block on the table.  Multiple tables are allowed to ask for</em>
<a name="659" href="#659">659</a>         <em class="comment">// ids simultaneously.</em>
<a name="660" href="#660">660</a>         <em class="comment">//        TableMap tMap = dbMap.getTable(tableName);</em>
<a name="661" href="#661">661</a>         <em class="comment">//        synchronized(tMap)  see comment in the getNextIds method</em>
<a name="662" href="#662">662</a>         <em class="comment">//        {</em>
<a name="663" href="#663">663</a>         <strong>if</strong> (adjustQuantity)
<a name="664" href="#664">664</a>         {
<a name="665" href="#665">665</a>             checkTiming(tableName);
<a name="666" href="#666">666</a>         }
<a name="667" href="#667">667</a> 
<a name="668" href="#668">668</a>         <strong>boolean</strong> useNewConnection = (connection == <strong>null</strong>) || (configuration
<a name="669" href="#669">669</a>                 .getBoolean(DB_IDBROKER_USENEWCONNECTION, <strong>true</strong>));
<a name="670" href="#670">670</a>         <strong>try</strong>
<a name="671" href="#671">671</a>         {
<a name="672" href="#672">672</a>             <strong>if</strong> (useNewConnection)
<a name="673" href="#673">673</a>             {
<a name="674" href="#674">674</a>                 connection = Transaction.beginOptional(databaseName,
<a name="675" href="#675">675</a>                     transactionsSupported);
<a name="676" href="#676">676</a>             }
<a name="677" href="#677">677</a> 
<a name="678" href="#678">678</a>             <em class="comment">// Write the current value of quantity of keys to grab</em>
<a name="679" href="#679">679</a>             <em class="comment">// to the database, primarily to obtain a write lock</em>
<a name="680" href="#680">680</a>             <em class="comment">// on the table/row, but this value will also be used</em>
<a name="681" href="#681">681</a>             <em class="comment">// as the starting value when an IDBroker is</em>
<a name="682" href="#682">682</a>             <em class="comment">// instantiated.</em>
<a name="683" href="#683">683</a>             quantity = getQuantity(tableName, connection);
<a name="684" href="#684">684</a>             updateQuantity(connection, tableName, quantity);
<a name="685" href="#685">685</a> 
<a name="686" href="#686">686</a>             <em class="comment">// Read the next starting ID from the ID_TABLE.</em>
<a name="687" href="#687">687</a>             BigDecimal[] results = selectRow(connection, tableName);
<a name="688" href="#688">688</a>             nextId = results[0]; <em class="comment">// NEXT_ID column</em>
<a name="689" href="#689">689</a> 
<a name="690" href="#690">690</a>             <em class="comment">// Update the row based on the quantity in the</em>
<a name="691" href="#691">691</a>             <em class="comment">// ID_TABLE.</em>
<a name="692" href="#692">692</a>             BigDecimal newNextId = nextId.add(quantity);
<a name="693" href="#693">693</a>             updateNextId(connection, tableName, newNextId.toString());
<a name="694" href="#694">694</a> 
<a name="695" href="#695">695</a>             <strong>if</strong> (useNewConnection)
<a name="696" href="#696">696</a>             {
<a name="697" href="#697">697</a>                 Transaction.commit(connection);
<a name="698" href="#698">698</a>             }
<a name="699" href="#699">699</a>         }
<a name="700" href="#700">700</a>         <strong>catch</strong> (Exception e)
<a name="701" href="#701">701</a>         {
<a name="702" href="#702">702</a>             <strong>if</strong> (useNewConnection)
<a name="703" href="#703">703</a>             {
<a name="704" href="#704">704</a>                 Transaction.rollback(connection);
<a name="705" href="#705">705</a>             }
<a name="706" href="#706">706</a>             <strong>throw</strong> e;
<a name="707" href="#707">707</a>         }
<a name="708" href="#708">708</a> 
<a name="709" href="#709">709</a>         List availableIds = (List) ids.get(tableName);
<a name="710" href="#710">710</a>         <strong>if</strong> (availableIds == <strong>null</strong>)
<a name="711" href="#711">711</a>         {
<a name="712" href="#712">712</a>             availableIds = <strong>new</strong> ArrayList();
<a name="713" href="#713">713</a>             ids.put(tableName, availableIds);
<a name="714" href="#714">714</a>         }
<a name="715" href="#715">715</a> 
<a name="716" href="#716">716</a>         <em class="comment">// Create the ids and store them in the list of available ids.</em>
<a name="717" href="#717">717</a>         <strong>int</strong> numId = quantity.<strong>int</strong>Value();
<a name="718" href="#718">718</a>         <strong>for</strong> (<strong>int</strong> i = 0; i &lt; numId; i++)
<a name="719" href="#719">719</a>         {
<a name="720" href="#720">720</a>             availableIds.add(nextId);
<a name="721" href="#721">721</a>             nextId = nextId.add(ONE);
<a name="722" href="#722">722</a>         }
<a name="723" href="#723">723</a>         <em class="comment">//        }</em>
<a name="724" href="#724">724</a>     }
<a name="725" href="#725">725</a> 
<a name="726" href="#726">726</a>     <em>/**<em>*</em></em>
<a name="727" href="#727">727</a> <em>     * This method allows you to get the number of ids that are to be</em>
<a name="728" href="#728">728</a> <em>     * cached in memory.  This is either stored in quantityStore or</em>
<a name="729" href="#729">729</a> <em>     * read from the db. (ie the value in ID_TABLE.QUANTITY).</em>
<a name="730" href="#730">730</a> <em>     *</em>
<a name="731" href="#731">731</a> <em>     * Though this method returns a BigDecimal for the quantity, it is</em>
<a name="732" href="#732">732</a> <em>     * unlikey the system could withstand whatever conditions would lead</em>
<a name="733" href="#733">733</a> <em>     * to really needing a large quantity, it is retrieved as a BigDecimal</em>
<a name="734" href="#734">734</a> <em>     * only because it is going to be added to another BigDecimal.</em>
<a name="735" href="#735">735</a> <em>     *</em>
<a name="736" href="#736">736</a> <em>     * @param tableName The name of the table we want to query.</em>
<a name="737" href="#737">737</a> <em>     * @param connection a Connection</em>
<a name="738" href="#738">738</a> <em>     * @return An int with the number of ids cached in memory.</em>
<a name="739" href="#739">739</a> <em>     */</em>
<a name="740" href="#740">740</a>     <strong>private</strong> BigDecimal getQuantity(String tableName, Connection connection)
<a name="741" href="#741">741</a>     {
<a name="742" href="#742">742</a>         BigDecimal quantity = <strong>null</strong>;
<a name="743" href="#743">743</a> 
<a name="744" href="#744">744</a>         <em class="comment">// If prefetch is turned off we simply return 1</em>
<a name="745" href="#745">745</a>         <strong>if</strong> (!configuration.getBoolean(DB_IDBROKER_PREFETCH, <strong>true</strong>))
<a name="746" href="#746">746</a>         {
<a name="747" href="#747">747</a>             quantity = <strong>new</strong> BigDecimal((<strong>double</strong>)1);
<a name="748" href="#748">748</a>         }
<a name="749" href="#749">749</a>         <em class="comment">// Initialize quantity, if necessary.</em>
<a name="750" href="#750">750</a>         <strong>else</strong> <strong>if</strong> (quantityStore.containsKey(tableName))
<a name="751" href="#751">751</a>         {
<a name="752" href="#752">752</a>             quantity = (BigDecimal) quantityStore.get(tableName);
<a name="753" href="#753">753</a>         }
<a name="754" href="#754">754</a>         <strong>else</strong>
<a name="755" href="#755">755</a>         {
<a name="756" href="#756">756</a>             Connection dbCon = <strong>null</strong>;
<a name="757" href="#757">757</a>             <strong>try</strong>
<a name="758" href="#758">758</a>             {
<a name="759" href="#759">759</a>                 <strong>if</strong> (connection == <strong>null</strong> || configuration
<a name="760" href="#760">760</a>                     .getBoolean(DB_IDBROKER_USENEWCONNECTION, <strong>true</strong>))
<a name="761" href="#761">761</a>                 {
<a name="762" href="#762">762</a>                     <em class="comment">// Get a connection to the db</em>
<a name="763" href="#763">763</a>                     dbCon = Torque.getConnection(databaseName);
<a name="764" href="#764">764</a>                 }
<a name="765" href="#765">765</a> 
<a name="766" href="#766">766</a>                 <em class="comment">// Read the row from the ID_TABLE.</em>
<a name="767" href="#767">767</a>                 BigDecimal[] results = selectRow(dbCon, tableName);
<a name="768" href="#768">768</a> 
<a name="769" href="#769">769</a>                 <em class="comment">// QUANTITY column.</em>
<a name="770" href="#770">770</a>                 quantity = results[1];
<a name="771" href="#771">771</a>                 quantityStore.put(tableName, quantity);
<a name="772" href="#772">772</a>             }
<a name="773" href="#773">773</a>             <strong>catch</strong> (Exception e)
<a name="774" href="#774">774</a>             {
<a name="775" href="#775">775</a>                 quantity = <strong>new</strong> BigDecimal((<strong>double</strong>)10);
<a name="776" href="#776">776</a>             }
<a name="777" href="#777">777</a>             <strong>finally</strong>
<a name="778" href="#778">778</a>             {
<a name="779" href="#779">779</a>                 <em class="comment">// Return the connection to the pool.</em>
<a name="780" href="#780">780</a>                 <strong>try</strong>
<a name="781" href="#781">781</a>                 {
<a name="782" href="#782">782</a>                     dbCon.close();
<a name="783" href="#783">783</a>                 }
<a name="784" href="#784">784</a>                 <strong>catch</strong> (Exception e)
<a name="785" href="#785">785</a>                 {
<a name="786" href="#786">786</a>                     log.error(<span class="string">"Release of connection failed."</span>, e);
<a name="787" href="#787">787</a>                 }
<a name="788" href="#788">788</a>             }
<a name="789" href="#789">789</a>         }
<a name="790" href="#790">790</a>         <strong>return</strong> quantity;
<a name="791" href="#791">791</a>     }
<a name="792" href="#792">792</a> 
<a name="793" href="#793">793</a>     <em>/**<em>*</em></em>
<a name="794" href="#794">794</a> <em>     * Helper method to select a row in the ID_TABLE.</em>
<a name="795" href="#795">795</a> <em>     *</em>
<a name="796" href="#796">796</a> <em>     * @param con A Connection.</em>
<a name="797" href="#797">797</a> <em>     * @param tableName The properly escaped name of the table to</em>
<a name="798" href="#798">798</a> <em>     * identify the row.</em>
<a name="799" href="#799">799</a> <em>     * @return A BigDecimal[].</em>
<a name="800" href="#800">800</a> <em>     * @exception Exception a generic exception.</em>
<a name="801" href="#801">801</a> <em>     */</em>
<a name="802" href="#802">802</a>     <strong>private</strong> BigDecimal[] selectRow(Connection con, String tableName)
<a name="803" href="#803">803</a>         throws Exception
<a name="804" href="#804">804</a>     {
<a name="805" href="#805">805</a>         StringBuffer stmt = <strong>new</strong> StringBuffer();
<a name="806" href="#806">806</a>         stmt.append(<span class="string">"SELECT "</span>)
<a name="807" href="#807">807</a>             .append(COL_NEXT_ID)
<a name="808" href="#808">808</a>             .append(<span class="string">", "</span>)
<a name="809" href="#809">809</a>             .append(COL_QUANTITY)
<a name="810" href="#810">810</a>             .append(<span class="string">" FROM "</span>)
<a name="811" href="#811">811</a>             .append(ID_TABLE)
<a name="812" href="#812">812</a>             .append(<span class="string">" WHERE "</span>)
<a name="813" href="#813">813</a>             .append(COL_TABLE_NAME)
<a name="814" href="#814">814</a>             .append(<span class="string">" = '"</span>)
<a name="815" href="#815">815</a>             .append(tableName)
<a name="816" href="#816">816</a>             .append('\'');
<a name="817" href="#817">817</a> 
<a name="818" href="#818">818</a>         Statement statement = <strong>null</strong>;
<a name="819" href="#819">819</a> 
<a name="820" href="#820">820</a>         BigDecimal[] results = <strong>new</strong> BigDecimal[2];
<a name="821" href="#821">821</a>         <strong>try</strong>
<a name="822" href="#822">822</a>         {
<a name="823" href="#823">823</a>             statement = con.createStatement();
<a name="824" href="#824">824</a>             ResultSet rs = statement.executeQuery(stmt.toString());
<a name="825" href="#825">825</a> 
<a name="826" href="#826">826</a>             <strong>if</strong> (rs.next())
<a name="827" href="#827">827</a>             {
<a name="828" href="#828">828</a>                 <em class="comment">// work around for MySQL which appears to support</em>
<a name="829" href="#829">829</a>                 <em class="comment">// getBigDecimal in the source code, but the binary</em>
<a name="830" href="#830">830</a>                 <em class="comment">// is throwing an NotImplemented exception.</em>
<a name="831" href="#831">831</a>                 results[0] = <strong>new</strong> BigDecimal(rs.getString(1)); <em class="comment">// next_id</em>
<a name="832" href="#832">832</a>                 results[1] = <strong>new</strong> BigDecimal(rs.getString(2)); <em class="comment">// quantity</em>
<a name="833" href="#833">833</a>             }
<a name="834" href="#834">834</a>             <strong>else</strong>
<a name="835" href="#835">835</a>             {
<a name="836" href="#836">836</a>                 <strong>throw</strong> <strong>new</strong> <a href="../../../../org/apache/torque/TorqueException.html">TorqueException</a>(<span class="string">"The table "</span> + tableName
<a name="837" href="#837">837</a>                         + <span class="string">" does not have a proper entry in the "</span> + ID_TABLE);
<a name="838" href="#838">838</a>             }
<a name="839" href="#839">839</a>         }
<a name="840" href="#840">840</a>         <strong>finally</strong>
<a name="841" href="#841">841</a>         {
<a name="842" href="#842">842</a>             <strong>if</strong> (statement != <strong>null</strong>)
<a name="843" href="#843">843</a>             {
<a name="844" href="#844">844</a>                 statement.close();
<a name="845" href="#845">845</a>             }
<a name="846" href="#846">846</a>         }
<a name="847" href="#847">847</a> 
<a name="848" href="#848">848</a>         <strong>return</strong> results;
<a name="849" href="#849">849</a>     }
<a name="850" href="#850">850</a> 
<a name="851" href="#851">851</a>     <em>/**<em>*</em></em>
<a name="852" href="#852">852</a> <em>     * Helper method to update a row in the ID_TABLE.</em>
<a name="853" href="#853">853</a> <em>     *</em>
<a name="854" href="#854">854</a> <em>     * @param con A Connection.</em>
<a name="855" href="#855">855</a> <em>     * @param tableName The properly escaped name of the table to identify the</em>
<a name="856" href="#856">856</a> <em>     * row.</em>
<a name="857" href="#857">857</a> <em>     * @param id An int with the value to set for the id.</em>
<a name="858" href="#858">858</a> <em>     * @exception Exception Database error.</em>
<a name="859" href="#859">859</a> <em>     */</em>
<a name="860" href="#860">860</a>     <strong>private</strong> <strong>void</strong> updateNextId(Connection con, String tableName, String id)
<a name="861" href="#861">861</a>         throws Exception
<a name="862" href="#862">862</a>     {
<a name="863" href="#863">863</a> 
<a name="864" href="#864">864</a> 
<a name="865" href="#865">865</a>         StringBuffer stmt = <strong>new</strong> StringBuffer(id.length()
<a name="866" href="#866">866</a>                                              + tableName.length() + 50);
<a name="867" href="#867">867</a>         stmt.append(<span class="string">"UPDATE "</span> + ID_TABLE)
<a name="868" href="#868">868</a>             .append(<span class="string">" SET "</span>)
<a name="869" href="#869">869</a>             .append(COL_NEXT_ID)
<a name="870" href="#870">870</a>             .append(<span class="string">" = "</span>)
<a name="871" href="#871">871</a>             .append(id)
<a name="872" href="#872">872</a>             .append(<span class="string">" WHERE "</span>)
<a name="873" href="#873">873</a>             .append(COL_TABLE_NAME)
<a name="874" href="#874">874</a>             .append(<span class="string">" = '"</span>)
<a name="875" href="#875">875</a>             .append(tableName)
<a name="876" href="#876">876</a>             .append('\'');
<a name="877" href="#877">877</a> 
<a name="878" href="#878">878</a>         Statement statement = <strong>null</strong>;
<a name="879" href="#879">879</a> 
<a name="880" href="#880">880</a>         <strong>if</strong> (log.isDebugEnabled())
<a name="881" href="#881">881</a>         {
<a name="882" href="#882">882</a>             log.debug(<span class="string">"updateNextId: "</span> + stmt.toString());
<a name="883" href="#883">883</a>         }
<a name="884" href="#884">884</a> 
<a name="885" href="#885">885</a>         <strong>try</strong>
<a name="886" href="#886">886</a>         {
<a name="887" href="#887">887</a>             statement = con.createStatement();
<a name="888" href="#888">888</a>             statement.executeUpdate(stmt.toString());
<a name="889" href="#889">889</a>         }
<a name="890" href="#890">890</a>         <strong>finally</strong>
<a name="891" href="#891">891</a>         {
<a name="892" href="#892">892</a>             <strong>if</strong> (statement != <strong>null</strong>)
<a name="893" href="#893">893</a>             {
<a name="894" href="#894">894</a>                 statement.close();
<a name="895" href="#895">895</a>             }
<a name="896" href="#896">896</a>         }
<a name="897" href="#897">897</a>     }
<a name="898" href="#898">898</a> 
<a name="899" href="#899">899</a>     <em>/**<em>*</em></em>
<a name="900" href="#900">900</a> <em>     * Helper method to update a row in the ID_TABLE.</em>
<a name="901" href="#901">901</a> <em>     *</em>
<a name="902" href="#902">902</a> <em>     * @param con A Connection.</em>
<a name="903" href="#903">903</a> <em>     * @param tableName The properly escaped name of the table to identify the</em>
<a name="904" href="#904">904</a> <em>     * row.</em>
<a name="905" href="#905">905</a> <em>     * @param quantity An int with the value of the quantity.</em>
<a name="906" href="#906">906</a> <em>     * @exception Exception Database error.</em>
<a name="907" href="#907">907</a> <em>     */</em>
<a name="908" href="#908">908</a>     <strong>private</strong> <strong>void</strong> updateQuantity(Connection con, String tableName,
<a name="909" href="#909">909</a>                                 BigDecimal quantity)
<a name="910" href="#910">910</a>         throws Exception
<a name="911" href="#911">911</a>     {
<a name="912" href="#912">912</a>         StringBuffer stmt = <strong>new</strong> StringBuffer(quantity.toString().length()
<a name="913" href="#913">913</a>                                              + tableName.length() + 50);
<a name="914" href="#914">914</a>         stmt.append(<span class="string">"UPDATE "</span>)
<a name="915" href="#915">915</a>             .append(ID_TABLE)
<a name="916" href="#916">916</a>             .append(<span class="string">" SET "</span>)
<a name="917" href="#917">917</a>             .append(COL_QUANTITY)
<a name="918" href="#918">918</a>             .append(<span class="string">" = "</span>)
<a name="919" href="#919">919</a>             .append(quantity)
<a name="920" href="#920">920</a>             .append(<span class="string">" WHERE "</span>)
<a name="921" href="#921">921</a>             .append(COL_TABLE_NAME)
<a name="922" href="#922">922</a>             .append(<span class="string">" = '"</span>)
<a name="923" href="#923">923</a>             .append(tableName)
<a name="924" href="#924">924</a>             .append('\'');
<a name="925" href="#925">925</a> 
<a name="926" href="#926">926</a>         Statement statement = <strong>null</strong>;
<a name="927" href="#927">927</a> 
<a name="928" href="#928">928</a>         <strong>if</strong> (log.isDebugEnabled())
<a name="929" href="#929">929</a>         {
<a name="930" href="#930">930</a>             log.debug(<span class="string">"updateQuantity: "</span> + stmt.toString());
<a name="931" href="#931">931</a>         }
<a name="932" href="#932">932</a> 
<a name="933" href="#933">933</a>         <strong>try</strong>
<a name="934" href="#934">934</a>         {
<a name="935" href="#935">935</a>             statement = con.createStatement();
<a name="936" href="#936">936</a>             statement.executeUpdate(stmt.toString());
<a name="937" href="#937">937</a>         }
<a name="938" href="#938">938</a>         <strong>finally</strong>
<a name="939" href="#939">939</a>         {
<a name="940" href="#940">940</a>             <strong>if</strong> (statement != <strong>null</strong>)
<a name="941" href="#941">941</a>             {
<a name="942" href="#942">942</a>                 statement.close();
<a name="943" href="#943">943</a>             }
<a name="944" href="#944">944</a>         }
<a name="945" href="#945">945</a>     }
<a name="946" href="#946">946</a> }
</pre>
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